The invention discloses a bone fracture plate device for the distal femur fracture. The bone fracture plate device comprises a main bone fracture plate body and an auxiliary bone fracture plate body. An arc-shaped protrusion is arranged at the position, close to the distal femur, of the bottom face of the main bone fracture plate body, multiple temporary screw holes are formed in the front end and the rear end of the arc-shaped protrusion respectively, and grooves are formed in the positions, around the arc-shaped protrusion, of the main bone fracture plate body. The auxiliary bone fracture plate body and the grooves are matched in size, an open groove corresponding to the arc-shaped protrusion is formed in the middle of the auxiliary bone fracture plate body, and screw holes corresponding to the temporary screw holes are formed in the front end and the rear end of the open groove. When the arc-shaped protrusion of the main bone fracture plate body is inserted into a positioning groove of the auxiliary bone fracture plate body, the auxiliary bone fracture plate body is embedded into the grooves of the main bone fracture plate body, and meanwhile the temporary screw holes correspond to the screw holes. Stable and firm fixation can be achieved, and eccentric fixation and bone nonunion are effectively avoided.